#include "md5.h"

typedef struct {
   UINT4 state[4]; /* state (ABCD) */
   UINT4 count[2];/* number of bits, modulo 2^64 (lsb first) */
   unsigned char buffer[64]; /* input buffer */
} MD5_CTX;

/*void MD5Init PROTO_LIST ((MD5_CTX *));
 * void MD5Update PROTO_LIST
 * ((MD5_CTX *, unsigned char *, unsigned int));
 * void MD5Final PROTO_LIST ((unsigned char [16], MD5_CT X *));
 *
 * static void MD5Transform PROTO_LIST ((UINT4 [4], unsigned char [64]));
 * static void Encode PROTO_LIST
 * ((unsigned char *, UINT4 *, unsigned int));
 * static void Decode PROTO_LIST
 * ((UINT4 *, unsigned char *, unsigned int));
 * static void MD5_memcpy PROTO_LIST ((POINTER, POINTER, unsigned int));
 * static void MD5_memset PROTO_LIST ((POINTER, int, unsigned int));
 * */
static unsigned char PADDING[64] = {
  0x80, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
  0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
  0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0
};

/* F, G, H and I are basic MD5 functions.
 * */
#define F(x, y, z) (((x) & (y)) | ((~x) & (z)))
#define G(x, y, z) (((x) & (z)) | ((y) & (~z)))
#define H(x, y, z) ((x) ^ (y) ^ (z))
#define I(x, y, z) ((y) ^ ((x) | (~z)))

/* ROTATE_LEFT rotates x left n bits.
 * */
#define ROTATE_LEFT(x, n) (((x) << (n)) | ((x) >> (32-(n))))

/* FF, GG, HH, and II transformations for rounds 1, 2, 3, and 4.
 * Rotation is separate from addition to prevent recomputation.
 * */
 
#define RL(x, y) (((x) << (y)) | ((x) >> (32 - (y)))) //xÏ×ѭ»·Òyλ

#define PP(x) (x<<24)|((x<<8)&0xff0000)|((x>>8)&0xff00)|(x>>24) //½«x¸ߵÍ»»¥»»,ÀÈPP(aabbccdd)=ddccbbaa

#define FF(a, b, c, d, x, s, ac) a = b + (RL((a + F(b,c,d) + x + ac),s))
#define GG(a, b, c, d, x, s, ac) a = b + (RL((a + G(b,c,d) + x + ac),s))
#define HH(a, b, c, d, x, s, ac) a = b + (RL((a + H(b,c,d) + x + ac),s))
#define II(a, b, c, d, x, s, ac) a = b + (RL((a + I(b,c,d) + x + ac),s))


void MD5Init (MD5_CTX *context);
void MD5Update(MD5_CTX *context, unsigned char *input,unsigned int inputLen);
 
void MD5Final (unsigned char digest[16], MD5_CTX *context);
static void MD5Transform(UINT4 [4], unsigned char [64]) ;
static void Encode(unsigned char *, UINT4 *, unsigned int);
static void Decode (UINT4 *, unsigned char *, unsigned int);
static void MD5_memcpy(POINTER, POINTER, unsigned int);
static void MD5_memset(POINTER, int, unsigned int);



/* MD5 initialization. Begins an MD5 operation, writing a new context.
 * */
void MD5Init (MD5_CTX *context)
  /* context */
{
  context->count[0] = context->count[1] = 0;
  /* Load magic initialization constants.
   * */
  context->state[0] = 0x67452301;
  context->state[1] = 0xefcdab89;
  context->state[2] = 0x98badcfe;
  context->state[3] = 0x10325476;
}

/* MD5 block update operation. Continues an MD5 message-digest
 * operation, processing another message block, and updating the
 * context.
 * */
void MD5Update (MD5_CTX *context, unsigned char *input,unsigned int inputLen)
  /* context */
  /* input block */
  /* length of input block */
{
  unsigned int i, index, partLen;

  /* Compute number of bytes mod 64 */
  index = (unsigned int)((context->count[0] >> 3) & 0x3F);

  /* Update number of bits */
  if ((context->count[0] += ((UINT4)inputLen << 3))
      < ((UINT4)inputLen << 3))
     context->count[1]++;
  context->count[1] += ((UINT4)inputLen >> 29);

  partLen = 64 - index;

  /* Transform as many times as possible.
   * */
  if (inputLen >= partLen) {
     MD5_memcpy
        ((POINTER)&context->buffer[index], (POINTER)input, partLen);
      MD5Transform (context->state, context->buffer);

       for (i = partLen; i + 63 < inputLen; i += 64)
          MD5Transform (context->state, &input[i]);

        index = 0;
  }
  else
     i = 0;

  /* Buffer remaining input */
  MD5_memcpy
     ((POINTER)&context->buffer[index], (POINTER)&input[i],
      inputLen-i);
}

/* MD5 finalization. Ends an MD5 message-digest operation, writing the
 * the message digest and zeroizing the context.
 * */
void MD5Final (unsigned char digest[16], MD5_CTX *context)
  /* message digest */
  /* context */
{
  unsigned char bits[8];
  unsigned int index, padLen;

  /* Save number of bits */
  Encode (bits, context->count, 8);

  /* Pad out to 56 mod 64.
   * */
  index = (unsigned int)((context->count[0] >> 3) & 0x3f);
  padLen = (index < 56) ? (56 - index) : (120 - index);
  MD5Update (context,(unsigned char*) PADDING, padLen);

  /* Append length (before padding) */
  MD5Update (context, bits, 8);
  /* Store state in digest */
  Encode (digest, context->state, 16);

  /* Zeroize sensitive information.
   * */
  MD5_memset ((POINTER)context, 0, sizeof (*context));
}

/* MD5 basic transformation. Transforms state based on block.
 * */
static void MD5Transform (UINT4 state[4],
    unsigned char block[64])
 
{
   
  UINT4 a = state[0], b = state[1], c = state[2], d = state[3], x[16];

  Decode (x, block, 64);

  FF (a, b, c, d, x[ 0], S11, 0xd76aa478); /* 1 */
  FF (d, a, b, c, x[ 1], S12, 0xe8c7b756); /* 2 */
  FF (c, d, a, b, x[ 2], S13, 0x242070db); /* 3 */
  FF (b, c, d, a, x[ 3], S14, 0xc1bdceee); /* 4 */
  FF (a, b, c, d, x[ 4], S11, 0xf57c0faf); /* 5 */
  FF (d, a, b, c, x[ 5], S12, 0x4787c62a); /* 6 */
  FF (c, d, a, b, x[ 6], S13, 0xa8304613); /* 7 */
  FF (b, c, d, a, x[ 7], S14, 0xfd469501); /* 8 */
  FF (a, b, c, d, x[ 8], S11, 0x698098d8); /* 9 */
  FF (d, a, b, c, x[ 9], S12, 0x8b44f7af); /* 10 */
  FF (c, d, a, b, x[10], S13, 0xffff5bb1); /* 11 */
  FF (b, c, d, a, x[11], S14, 0x895cd7be); /* 12 */
  FF (a, b, c, d, x[12], S11, 0x6b901122); /* 13 */
  FF (d, a, b, c, x[13], S12, 0xfd987193); /* 14 */
  FF (c, d, a, b, x[14], S13, 0xa679438e); /* 15 */
  FF (b, c, d, a, x[15], S14, 0x49b40821); /* 16 */

  GG (a, b, c, d, x[ 1], S21, 0xf61e2562); /* 17 */
  GG (d, a, b, c, x[ 6], S22, 0xc040b340); /* 18 */
  GG (c, d, a, b, x[11], S23, 0x265e5a51); /* 19 */
  GG (b, c, d, a, x[ 0], S24, 0xe9b6c7aa); /* 20 */
  GG (a, b, c, d, x[ 5], S21, 0xd62f105d); /* 21 */
  GG (d, a, b, c, x[10], S22,0x2441453); /* 22 */
  GG (c, d, a, b, x[15], S23, 0xd8a1e681); /* 23 */
  GG (b, c, d, a, x[ 4], S24, 0xe7d3fbc8); /* 24 */
  GG (a, b, c, d, x[ 9], S21, 0x21e1cde6); /* 25 */
  GG (d, a, b, c, x[14], S22, 0xc33707d6); /* 26 */
  GG (c, d, a, b, x[ 3], S23, 0xf4d50d87); /* 27 */
  GG (b, c, d, a, x[ 8], S24, 0x455a14ed); /* 28 */
  GG (a, b, c, d, x[13], S21, 0xa9e3e905); /* 29 */
  GG (d, a, b, c, x[ 2], S22, 0xfcefa3f8); /* 30 */
  GG (c, d, a, b, x[ 7], S23, 0x676f02d9); /* 31 */
  GG (b, c, d, a, x[12], S24, 0x8d2a4c8a); /* 32 */

  /* Round 3 */
  HH (a, b, c, d, x[ 5], S31, 0xfffa3942); /* 33 */
  HH (d, a, b, c, x[ 8], S32, 0x8771f681); /* 34 */
  HH (c, d, a, b, x[11], S33, 0x6d9d6122); /* 35 */
  HH (b, c, d, a, x[14], S34, 0xfde5380c); /* 36 */
  HH (a, b, c, d, x[ 1], S31, 0xa4beea44); /* 37 */
  HH (d, a, b, c, x[ 4], S32, 0x4bdecfa9); /* 38 */
  HH (c, d, a, b, x[ 7], S33, 0xf6bb4b60); /* 39 */
  HH (b, c, d, a, x[10], S34, 0xbebfbc70); /* 40 */
  HH (a, b, c, d, x[13], S31, 0x289b7ec6); /* 41 */
  HH (d, a, b, c, x[ 0], S32, 0xeaa127fa); /* 42 */
  HH (c, d, a, b, x[ 3], S33, 0xd4ef3085); /* 43 */
  HH (b, c, d, a, x[ 6], S34,0x4881d05); /* 44 */
  HH (a, b, c, d, x[ 9], S31, 0xd9d4d039); /* 45 */
  HH (d, a, b, c, x[12], S32, 0xe6db99e5); /* 46 */
  HH (c, d, a, b, x[15], S33, 0x1fa27cf8); /* 47 */
  HH (b, c, d, a, x[ 2], S34, 0xc4ac5665); /* 48 */

  /* Round 4 */
  II (a, b, c, d, x[ 0], S41, 0xf4292244); /* 49 */
  II (d, a, b, c, x[ 7], S42, 0x432aff97); /* 50 */
  II (c, d, a, b, x[14], S43, 0xab9423a7); /* 51 */
  II (b, c, d, a, x[ 5], S44, 0xfc93a039); /* 52 */
  II (a, b, c, d, x[12], S41, 0x655b59c3); /* 53 */
  II (d, a, b, c, x[ 3], S42, 0x8f0ccc92); /* 54 */
  II (c, d, a, b, x[10], S43, 0xffeff47d); /* 55 */
  II (b, c, d, a, x[ 1], S44, 0x85845dd1); /* 56 */
  II (a, b, c, d, x[ 8], S41, 0x6fa87e4f); /* 57 */
  II (d, a, b, c, x[15], S42, 0xfe2ce6e0); /* 58 */
  II (c, d, a, b, x[ 6], S43, 0xa3014314); /* 59 */
  II (b, c, d, a, x[13], S44, 0x4e0811a1); /* 60 */
  II (a, b, c, d, x[ 4], S41, 0xf7537e82); /* 61 */
  II (d, a, b, c, x[11], S42, 0xbd3af235); /* 62 */
  II (c, d, a, b, x[ 2], S43, 0x2ad7d2bb); /* 63 */
  II (b, c, d, a, x[ 9], S44, 0xeb86d391); /* 64 */

  state[0] += a;
  state[1] += b;
  state[2] += c;
  state[3] += d;

  /* Zeroize sensitive information.
   * */
  MD5_memset ((POINTER)x, 0, sizeof (x));
}

/* Encodes input (UINT4) into output (unsigned char). Assumes len is
 * a multiple of 4.
 * */
static void Encode (unsigned char *output,
    UINT4 *input,
    unsigned int len)
 
{
  unsigned int i, j;

  for (i = 0, j = 0; j < len; i++, j += 4) {
     output[j] = (unsigned char)(input[i] & 0xff);
     output[j+1] = (unsigned char)((input[i] >> 8) & 0xff);
     output[j+2] = (unsigned char)((input[i] >> 16) & 0xff);
     output[j+3] = (unsigned char)((input[i] >> 24) & 0xff);
  }
}

/* Decodes input (unsigned char) into output (UINT4). Assumes len is
 * a multiple of 4.
 * */
static void Decode (UINT4 *output,
    unsigned char *input,
    unsigned int len)
{
  unsigned int i, j;

  for (i = 0, j = 0; j < len; i++, j += 4)
     output[i] = ((UINT4)input[j]) | (((UINT4)input[j+1]) << 8) |
        (((UINT4)input[j+2]) << 16) | (((UINT4)input[j+3]) << 24);
}

/* Note: Replace "for loop" with standard memcpy if possible.
 * */

static void MD5_memcpy (POINTER output,
    POINTER input,
    unsigned int len)
{
  unsigned int i;

  for (i = 0; i < len; i++)
    output[i] = input[i];
}

/* Note: Replace "for loop" with standard memset if possible.
 * */
static void MD5_memset (POINTER output,
    int value,
    unsigned int len)
{
  unsigned int i;

  for (i = 0; i < len; i++)
     ((char *)output)[i] = (char)value;
}

/* Digests a string and prints the result.
 * */
char* MDString (char *string) 
{
  MD5_CTX context;
  unsigned char digest[16];
  char output1[32];
  static char output[33]={""};
  unsigned int len = strlen (string);
  int i;
  MD5Init (&context);
  MD5Update (&context, (unsigned char*)string, len);
  MD5Final (digest, &context);

  for (i = 0; i < 16; i++) {
    sprintf(&(output1[2*i]),"%02x",(unsigned char)digest[i]);
    sprintf(&(output1[2*i+1]),"%02x",(unsigned char)(digest[i]<<4));
  }
  for(i=0;i<32;i++)
    output[i]=output1[i];
  return output;
}
 

char* hmac_md5(char* text,char*key) {
  char digest[16];
  char output1[32];
  static char output[33]={""};
  MD5_CTX context;
  unsigned char k_ipad[65];/* inner padding -
                              * key XORd with ipad
                              * */
  unsigned char k_opad[65];/* outer padding -
                              * key XORd with opad
                              * */
  unsigned char tk[16];
  int i;
  int text_len = strlen (text);
  int key_len=strlen(key);
  /* if key is longer than 64 bytes reset it to key=MD5(key) */
  if (key_len > 64) {

    MD5_CTX tctx;

    MD5Init(&tctx);
    MD5Update(&tctx,(unsigned char*) key, key_len);
    MD5Final(tk, &tctx);

    key = (char*)tk;
    key_len = 16;
  }

  /*
   *  * the HMAC_MD5 transform looks like:
   *   *
   *    * MD5(K XOR opad, MD5(K XOR ipad, text))
   *     *
   *      * where K is an n byte key
   *       * ipad is the byte 0x36 repeated 64 times
   *        * opad is the byte 0x5c repeated 64 times
   *         * and text is the data being protected
   *          */

  /* start out by storing key in pads */
   
  /*bzero( k_ipad, sizeof k_ipad);
   * bzero( k_opad, sizeof k_opad);
   * */

  for(i=0;i<65;i++)
    k_ipad[i]=(unsigned char)0;
  for(i=0;i<65;i++)
    k_opad[i]=(unsigned char)0;

  /*bcopy( key, k_ipad, key_len);
   * bcopy( key, k_opad, key_len);
   *  */
  for(i=0;i<key_len;i++) { 
    k_ipad[i]=(unsigned char)key[i];
    k_opad[i]=(unsigned char)key[i];
  }

  /* XOR key with ipad and opad values */
  for (i=0; i<64; i++) {
    k_ipad[i] ^= 0x36;
    k_opad[i] ^= 0x5c;
  }
  /*
   *  * perform inner MD5
   *   */
  MD5Init(&context); /* init context for 1st
                        * pass */
  MD5Update(&context, k_ipad, 64);/* start with inner pad */
  MD5Update(&context, (unsigned char*)text, text_len); /* then text of datagram

                                                          */
  MD5Final((unsigned char*)digest, &context);/* finish up 1st pass */
  /*
   *  * perform outer MD5
   *   */
  MD5Init(&context); /* init context for 2nd
                        * pass */
  MD5Update(&context, k_opad, 64); /* start with outer pad */
  MD5Update(&context,(unsigned char*) digest, 16); /* then results of 1st
                                                      * hash */
  MD5Final((unsigned char*)digest, &context);/* finish up 2nd pass */
  for (i = 0; i < 16; i++) {
     sprintf(&(output1[2*i]),"%02x",(unsigned char)digest[i]);
     sprintf(&(output1[2*i+1]),"%02x",(unsigned char)(digest[i]<<4));
  }
  for(i=0;i<32;i++)
    output[i]=output1[i];
  return output;
}

